In the May 11 & 25 SN: High-tech cricket farming, AI learns from Minecraft, looking for lithium, a new hominid species is named, signs of life in dead pig brains, Cherokee cave texts decoded, water molecules on the moon and more.

Until now, evidence of humans colonizing this high-altitude region extended no further back than around 8,000 years ago (SN: 2/4/17, p. 8). Some researchers have argued that the first permanent settlers arrived perhaps 12,000 to 13,000 years ago.

Archaeologist Xiaoling Zhang of the Chinese Academy of Sciences in Beijing and her colleagues excavated a much older site than that, called Nwya Devu, on the Tibetan Plateau. Three sediment layers contained a total of 3,683 stone artifacts made from local, high-quality rock, the researchers report in the Nov. 30 Science.

Based on estimates of the time since each soil layer had been buried, people occupied the site from about 40,000 to 30,000 years ago, then from roughly 25,000 to 18,000 years ago, and finally from around 13,000 to 4,000 years ago. Zhang’s group suspects people used the site as a workshop where they made a variety of stone tools, including long, rectangular blades that could be used for cutting or scraping.

Ecological conditions on the Tibetan Plateau during the late Stone Age would have enabled seasonal visits by people who could have hunted prey such as gazelles and yaks, the researchers say.